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Describe the five processes which allow the transport across the cell membrane. Structure of a plasma membrane: The cell membrane is semi-permeable membrane that is made up of proteins, carbohydrates and phospholipid molecules. There are different types of protein molecules randomly embedded in the bi-layer which carry out various cell functions like cell-cell contact, surface recognition, cytoskeleton contact, signalling, enzyme activity, or transporting substances across the membrane. The types of proteins in the membrane are Transport channel proteins, Globular proteins, Glycoprotein's, Peripheral, Integral, and Surface proteins and Alpha-Helix proteins. These proteins make up around 50% of the membrane where as only 5% is made up from carbohydrates. The cell membrane has phospholipids, glycolipids, and steroids present in it. Other lipids present are the cholesterol molecule which helps maintain the fluid condition in the bi-layer. The phospholipid molecules form the outer and inner layers (bi-layer) and are constantly moving giving a fluid like structure....

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